<%--
  Created by IntelliJ IDEA.
  User: Albert Lee
  Date: 2020/5/26
  Time: 17:14
  To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%@ page import="java.sql.*"%>

<%

    String path = request.getContextPath();

    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

  <head>

        <base href="<%=basePath%>">
        <title>学生信息</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">


     <script type="text/javascript">

        function validate() {
        var id = document.forms[0].id.value;
        var name = document.forms[0].name.value;
        var age = document.forms[0].age.value;
        var gender = document.forms[0].gender.value;
        var major = document.forms[0].major.value;

        if(id <= 0){
            alert("学号不能为空，请输入学号！");
            return false;
        } else if(name.length <= 0){
            alert("姓名不能为空，请输入姓名！");
            return false;
        } else if(age <= 0){
            alert("请输入合法年龄！");
            return false;
        } else if(gender.length <= 0){
            alert("请选择性别！");
            return false;
        } else if(major.length <= 0){
            alert("专业不能为空，请输入所学专业！");
            return false;
        } else{
            return true;
        }

         //document.getElementById("form").submit();

        }

        </script>
    </head>



    <body >

        <%
        response.setCharacterEncoding("UTF-8");
        request.setCharacterEncoding("UTF-8");

        String id = request.getParameter("id");
        Connection conn = null;
        Statement stat = null;
        ResultSet rs = null;
        Class.forName("com.mysql.cj.jdbc.Driver");
        String url = "jdbc:mysql://localhost:3306/student";
        String user = "root";
        String password = "123456";
        conn = DriverManager.getConnection(url,user,password);
        stat = conn.createStatement();

        rs = stat.executeQuery("select * from stu where id=" + id + "");

        %>

        <br>
        <h2>学生信息</h2>  <hr>    
        <br>
        <h3>要修改的学生信息如下</h3>
        <table width="450" border="100" cellSpacing=1 style="font-size:15pt;border:dashed 1pt">
        <tr>
        <td>学号</td>
        <td>姓名</td>
        <td>年龄</td>
        <td>性别</td>
        <td>专业</td>
        </tr>
        <%

        while(rs.next()) {
        out.print("<tr>");
        out.print("<td>" + rs.getInt("id") + "</td>");
        out.print("<td>" + rs.getString("name") + "</td>");
        out.print("<td>" + rs.getInt("age") + "</td>");
        out.print("<td>" + rs.getString("gender") + "</td>");
        out.print("<td>" + rs.getString("major") + "</td>");
        out.print("</tr>");

        %>
        </table>
        <br>
        <br>
        <h3>将学生信息更改为：</h3>

    <form action="doupdate.jsp" method="post" onSubmit="return validate()">
        <h4> 学号：<input type="text" name="id" value="<%=rs.getInt("id") %>" title="学号不能改变" readonly="readonly"></input><br></h4>
        <h4>  姓名：<input type="text" name="name" value="<%=rs.getString("name") %>" title="姓名不能为空" ></input><br></h4>
        <h4>  年龄：<input type="text" name="age" value="<%=rs.getInt("age") %>" title="年龄不能为空"></input><br></h4>
        <h4>  性别：<input type="radio" name="gender"  value="男" >男
                    <input type="radio" name="gender" value="女" >女<br></h4>
        <h4>  专业：<input type="text" name="major" value="<%=rs.getString("major") %>" title="专业不能为空"></input><br></h4>
        <input type="submit" value="修改"/>
    </form>

        <br>
        <h3><a href=addStuInfo.jsp>返回添加信息页面</a></h3>

    <h3><a href=showInfo.jsp>返回信息查询页面</a></h3>

    <%
    }
    %>

    <%

    if(rs != null) {
          rs.close();
          rs = null;
    }
    if(stat != null) {
          stat.close();
          stat = null;
    }
    if(conn != null) {
        conn.close();
        conn = null;
    }
        %>
    </body>

    </html>